Nowadays, non-renewable energy resources are becoming less and less, and even some energy has been consumed, therefore, as wave energy, combustible ice, coal bed gas and microbes, these energy sources will become the new energy widely used by human. Wind power, as a renewable energy, has been brought into use in many areas and equipment, and its technology is becoming mature slowly. Modern wind power generator mainly comprises horizontal axis wind power generator and vertical axis wind power generator. Vertical axis product and horizontal axis product are different. In vertical axis wind power generator, the rotating shaft is installed on the vertical axis, perpendicular to the ground, not affected by the wind direction when the vertical axis wind power generator are working, so no adjustment are required when the wind direction changes.
Wherein, Darrieus turbine belongs to one of the vertical wind power generator, the turbine is comprised of a vertical rotating shaft, a top rotor center on the top of the rotating shaft, blades, a bottom rotor center on the bottom of the rotating shaft, a gearbox connected to the rotating shaft, a generator connected to the gearbox. The upper end of the blades connects at the top rotor center, and lower end of the blades connects at the bottom center, driving the vertical rotating shaft to rotate after the blades rotates, and the rotating shaft transfers the power to the generator by the gearbox provided on the bottom, so as to make the generator generate electricity. Because such wind power generator is too big, the rotating shaft is usually high, in order to strengthen its stability, by dragline from the top of the rotating shaft to the bottom surface, even though the rotating shaft is strengthened, its occupied area is bigger, which undermines efficient use of the land; in addition, the power transmission chain is too long in the wind power generation process, therefore the power losses too much energy in the course of transmitting, which is not conducive to efficient use of energy; furthermore, only can the power generating device generate electricity when it comprises the gearbox, generator, transmission shaft and other sets of components, and the structure of the power generating device is complex, once the power generating device breaks down, its maintenance and repairs are too difficult and only can the large components be lift when erecting the tower crane besides the generator, therefore, the maintenance cost is high and the maintenance time is long, which directly affects the working efficiency of the wind power generator.
In the vertical wind power generator of application No. 200910038122.9 filed by the present applicant, it comprises a tower column, a generator and at least two blades, and at least one power generating device is provided on the tower column; the power generating device is comprised of a first lower flange plate and a first upper flange plate, a first bearing block, a first bearing, a first generator, a generator central column, a second bearing, a second bearing block, a second lower flange plate and a second upper flange plate; the first lower flange plate is fixed with the tower column, the first upper flange plate is located on the first lower flange plate and fixedly connects to the first lower flange plate, the first bearing block is fixed on the first upper flange plate, the first bearing is comprised of a first outer ring, a first steel ball group and a first inner ring, the first inner ring is fixed on the first bearing block, and the first outer ring and the first steel ball group can rotate around the first inner ring; the first generator comprises a first inner stator and a first outer rotor, the first inner stator is located on the first inner ring, and the first outer rotor is located on the first outer ring and fixedly connects to the first outer ring; the generator central column fixedly connects to the first inner stator; the second bearing, the second bearing block, the second lower flange plate and the second upper flange plate are provided above the generator central column in sequence, the second upper flange plate is fixed with the tower column, the second lower flange plate is located below the second upper flange plate and fixedly connects to the second upper flange plate, the second bearing block is located below the second lower flange plate and fixedly connects to the second lower flange plate, the second bearing is comprised of the second outer ring, the second steel ball group and the second inner ring, the second inner ring is located below the second bearing block and fixedly connects to the second bearing block, and the second outer ring and the second steel ball group can rotate around the second inner ring; the upper end of the blades fixedly connects to the second outer ring, and the lower end of the blades fixedly connects to the first outer ring. This kind of invention has simple structure, safe, occupies less area, cost less, and has high utilization efficiency of wind power; however, it has high requirements for the bearing, the size of the outer ring of the bearing needs to be equal to that of the outer rotor of the generator, the larger the generator is, the larger the needed diameter of the bearing is. A large bearing causes high production costs, a bearing with a diameter of 5 m needs about 300-400 thousand, and that with a diameter of 3 m needs hundreds of thousands, on the other hand, it is not easy to assemble a large bearing.
In wind power generator, high and low utilization efficiency of wind power depends on the construction and the structure of the blade; nowadays, the shape of a blade of a vertical wind power generator varied, such as fan-shaped structure, the sail-shaped structure, φ-shaped structure, etc., in these structures, φ-shaped structure has the highest utilization efficiency of wind energy, but due to changes in wind speed and wind power is uncertain, resulting in the size of the windward side of the blade out of control, therefore, it's difficult to prevent the failure and even damage of the vertical wind power generator caused by excessive wind speed.
The generator will produce heat at work, in particular the high-power generator, if not cooling the generator, the generator will be burned, reducing the life of the generator. Nowadays, the normally conducted cooling method is water cooling or installing a fan in one end of the generator. Conducting the method of water cooling, it needs to layout a lot of waterway, which has complex structure and is difficult to achieve the required water seal, causing the damage of the motor insulation, and affecting the life of the motor; an outer rotor energy saving wind power generator is disclosed in Chinese patent of No. 200520032333.9, comprising an outer rotor, a stator, a fixing shaft and a bearing, the stator is fixed on the fixing shaft, the outer rotor is fixedly installed on the bearing through the upper and lower end cover by the magnet installed on the shell and inner wall, there are louvers on the two ends of said shell. In this structure, because part of the heat of the generator evolutes through the louvers, there is no heat exchange in the whole structure, causing poor heat dissipation.
With further study of wind power generator, when it works, the blades suffer strong wind; therefore, this requires a larger capacity of blades, there is a kind of vertical wind power generator, comprising at least one generator unit; the said generator unit includes a stand column, a generator and at least two blades; the said generator includes a stator and a rotor, the stator is provided on the stand column, and the rotor is provided outside of the stator; a first flange is provided on the lower end of the said rotor, and connects to the rotor; a first bearing on the lower end of the first flange on the stand column, and the outer ring of the first bearing connects to the first flange; a second flange is provided on the upper end of the said rotor, and the second flange connects to the rotor; a second bearing is provided on the upper end of the second flange on the stand column, and the outer ring of the second bearing connects to the second flange; a third bearing is provided above of the second bearing on the stand column, the upper end of the said blades connect to the outer ring of the third bearing, and the lower end of the blades connect to the outer ring of the second bearing. The vertical wind power generator with this kind of structure, the movement of the blades drives the rotor to rotate through the second bearing and the second flange, the torque of the rotor is provided by the blades and mainly provided by the lower end of the blades; because the lower end of the blades connects the generator as load, when the vertical wind power generator works, the deformation of the lower end of the blades is small, and that of the upper end of the blades is large, which causes the stresses on the upper end and lower end of the blades are different, therefore, the blades to damage easily.